1. Field of the Invention
The subject invention is related to the picture-in-picture (PIP) feature for a television display.
2. Description of Related Art
Currently, digital television sets with PIP have been developed. These sets superimpose scaled-down 4:3 aspect ratio images over a main full screen video picture allowing the user to view multiple programs simultaneously. However, due to the superimposition, portions of the main video picture information are lost at the locations of the PIP images.
As the broadcast and television industry moves toward the development of a high definition television (HDTV) standard, a new picture size aspect ratio of 16:9 has become the preferred size for wide-screen and HDTV. In order to be compatible with standard NTSC programming material, any wide-screen hardware must be capable of displaying 4:3 aspect ratio video on the wider 16:9 screens. Given that the picture height is the same for both aspect ratios, then: EQU (16/9)/(4/3)=1.33
Thus, the wide-screen format has 33% more picture width than the conventional 4:3 format. Conversely, when a 4:3 video image is displayed on the wide-screen display, 25% of the available viewing area (typically, the width) will remain unused.
Co-pending U.S. patent application Ser. No. 07/304,736, filed Jan. 31, 1989, to Guerinot et al. and assigned to the assignee of the subject application, discloses a method and apparatus for dithering a 4:3 aspect ratio picture on a 16:9 aspect ratio display to prevent uneven phosphor burn-in. However, the above-noted 25% of the viewing area remains unused.